Evaluation of a New Topical Treatment for the Control of Cutaneous Leishmaniasis

Development of a topical treatment for tegumentary leishmaniasis using 8-hydroxyquinoline

In the context of neglected diseases, tegumentary leishmaniasis (TL) presents an emerging and re-emerging character in the national territory and in the world. The treatment of TL has limitations, such as intravenous administration route, high toxicity, and high treatment costs. Thus, several researchers work on new therapeutic strategies to improve the effectiveness of the treatment of leishmaniasis. In this light, the present study used a topical formulation, containing 8-hydroquinoline (8-HQN), for the treatment of Balb/c mice infected with L. amazonensis. After the treatment, the mean diameter of the lesion was measured, as well as the parasite load in organs and immunological parameters associated with the treatment. The results showed that the animals treated with 8-HQN 5%, when compared to controls, showed a reduction in the mean diameter of the lesion and in the parasite load. The animals treated with the ointment showed a type 1 cellular immune response profile associated with the production of cytokines such as INF-γ and TNF-α. In addition, the treatment did not demonstrate toxicity to mice. Therefore, the topical formulation containing 8-HQN 5% is a promising candidate in the topical treatment and could be considered, in the future, as an alternative for the treatment of TL.

Andrographolide-Soya-L-α-Phosphatidyl Choline Complex Augmented Solubility and Drug Delivery in Leishmania donovani, a Causative Agent for Cutaneous and Visceral Leishmaniasis

The utility of andrographolide (AN) in visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) is limited owing to poor solubility, hindered permeation, and unstable structure under physiological conditions. The present study mainly focuses on synthesizing of andrographolide-Soya-L-α-phosphatidyl choline (ANSPC) complex in ethanol and its characterization using various spectral and analytical techniques. Results from FT-IR, ¹H NMR, ROSEY, and in silico docking techniques suggest ANSPC complex formation due to inter-molecular interaction between the hydrophilic head of SPC and hydroxyl group of AN present at 24th position. ANSPC complex demonstrated the solubility of 113.93 ± 6.66 μg/mL significantly (P < 0.05) greater than 6.39 ± 0.47 μg/mL of AN. The particle size of ANSPC complex was found to be 182.2 ± 2.69 nm. The IC₅₀ value of AN suspension (PBS, pH ~ 7.4) at 24, 48, and 72 h against Leishmania donovani (L. donovani) was noticed to be 32.76 ± 4.53, 20.87 ± 2.37, and 17.71 ± 3.06 μM/mL, respectively. Moreover, augmented aqueous solubility of ANSPC complex led to significant (P < 0.05) reduction in IC₅₀ value, i.e., 25.02 ± 4.35, 11.31 ± 0.60, and 8.33 ± 2.71 μM/mL at 24, 48, and 72 h, respectively. The IC₅₀ values for miltefosine were noted to be 9.84 ± 2.65, 12.13 ± 7.26, and 6.56 ± 0.61 μM/mL at similar time periods. Moreover, ANSPC complex demonstrated augmented cellular uptake at 24 h as compared to 6 h in L. donovani. We suppose that submicron size and phospholipid-mediated complexation might have endorsed the permeation of ANSPC complex across the plasma membrane of L. donovani parasite by transport mechanisms such as P-type ATPase. ANSPC complex warrants further in-depth in vivo studies under a set of stringent parameters for translating the product into a clinically viable form.

Nutritional Modulation of the Immune Response Mediated by Nucleotides in Canine Leishmaniosis

Leishmaniasis is an emerging, uncontrolled, and neglected zoonotic disease. Climate change is contributing to its ongoing global expansion. The dog is the main reservoir; hence the importance of implementing effective treatment, prevention, and control measures in this animal species to protect public health. However, although the standard treatment for canine leishmaniosis (CanL) is effective, it does not provide full parasitological clearance, and side effects and drug resistance have been described. The host's immune system plays a key role in the establishment and evolution of leishmaniasis. Dietary nucleotides modulate the immune response and, given their reported efficacy and safety in sick and clinically healthy Leishmania-infected dogs and because they represent a sustainable option with no associated side effects or resistance, they could be included within the prevention, treatment, and control strategies for leishmaniasis. This article briefly summarizes the scientific literature on CanL management, including unresolved issues, and reviews the scientific evidence on immunomodulatory effects of dietary nucleotides in different animal species. It also proposes a CanL management algorithm, including nucleotides. It is concluded that nutritional modulation of the immune response with nucleotides can contribute to better management of leishmaniasis following a One Health approach, especially in the COVID-19 era.

The effects of medicinal herbs and marine natural products on wound healing of cutaneous leishmaniasis: A systematic review

This study aimed to investigate the effects of medicinal herbs and marine natural products on wound healing of cutaneous leishmaniasis. To carry out this literature review, the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) instructions were used. Articles on the potential of medicinal plants and natural substances of marine origin against wound healing of cutaneous leishmaniasis were explored. The scientific databases considered were PubMed, Science Direct, Google Scholar, Web of Science, Scopus, and SpringerLink. The scientific documents collected were mainly scientific articles, books, book chapters, and doctoral thesis. The research considered 73 manuscripts published in the period from 1990 to 2020. From all the data collected, it appears that the scientific literature is rich in medicinal herbs and marine products to be valorized in the wound healing of cutaneous leishmaniasis. We have identified 15 medicinal plants traditionally used in the management of healing or ulcer of cutaneous leishmaniasis, 32 medicinal plants whose efficacy has been demonstrated in vitro or in vivo against cutaneous leishmaniasis, 5 marine products active against cutaneous leishmaniasis. It is also clear that the option of medicinal herbs/marine products in the management of cutaneous leishmaniasis is less expensive and allows to avoid the side effects of conventional products. It is necessary to encourage the development of dermatological topicals for the management of cutaneous leishmaniasis based on the data collected. In vivo research should be intensified on medicinal herbs traditionally used in wound healing of cutaneous leishmaniasis.